Stelvio

The Stelvio is the transmission we set out to build first: a twelve-speed sealed gearbox for trail and all-mountain riding, mounted at the crank where its mass belongs — low and centered in the frame. The 510% range covers steep technical climbs and fast fire-road descents on a single chainring-free drivetrain, with even steps of roughly 16% between gears so cadence changes stay predictable.

Because the gearset lives inside a sealed, oil-bathed housing, the parts that wear on a conventional drivetrain — cassette, derailleur, jockey wheels — simply are not there. The chain (or belt) runs in a straight line on a single cog, which means no cross-chaining losses and a chainline that never moves. Sprung mass at the rear wheel drops, and suspension tuning stops fighting the weight of a cassette.

The housing is machined from 7075-T6 billet in our Charlotte facility, then hard-anodized. Internals are case-hardened steel, shot-peened at the gear roots. We designed the Stelvio to be rebuilt, not replaced: every seal, bearing, and gear pair is serviceable with standard tools and published torque specs.